I just did 2 kegs (IIPA and Imp. Stout) in 2 days at 30 PSI. It's really wasy to over shoot your carb volume though, so be careful. I was on a deadline for a vacation, and WAY over shot the stout
And this is assuming your beer is cold. It won't work at room temp.
I have a single body reg in my little 3-keg Haier kegerator. It's good for serving, and for set and forget. While I'm drinking 2 kegs, the 3rd is carbonating to just the right volume in the back. When I kick a keg I pull the dead one, move the (now carbonated) keg to the front, and install a new un-carbonated keg in the back to "set and forget" again
It works great as long as you don't kick more than 2 kegs every 2 weeks